1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136

//! The native `json` module for the [Rune Language].
//!
//! [Rune Language]: https://rune-rs.github.io
//!
//! ## Usage
//!
//! Add the following to your `Cargo.toml`:
//!
//! ```toml
//! rune-modules = { version = "0.13.2", features = ["json"] }
//! ```
//!
//! Install it into your context:
//!
//! ```rust
//! let mut context = rune::Context::with_default_modules()?;
//! context.install(rune_modules::json::module(true)?)?;
//! # Ok::<_, rune::support::Error>(())
//! ```
//!
//! Use it in Rune:
//!
//! ```rust,ignore
//! use json;
//!
//! fn main() {
//!     let data = json::from_string("{\"key\": 42}");
//!     dbg(data);
//! }
//! ```

use rune::{ContextError, Module, vm_write, Any};
use rune::runtime::{Bytes, Value, Formatter};
use rune::alloc::{Vec, String};
use rune::alloc::fmt::TryWrite;

#[rune::module(::json)]
/// Module for processing JSON.
///
/// # Examples
///
/// ```rune
/// let object = #{"number": 42, "string": "Hello World"};
/// let object = json::from_string(json::to_string(object)?)?;
/// assert_eq!(object, #{"number": 42, "string": "Hello World"});
/// ```
pub fn module(_stdio: bool) -> Result<Module, ContextError> {
    let mut module = Module::from_meta(self::module_meta)?;
    module.ty::<Error>()?;
    module.function_meta(Error::display)?;
    module.function_meta(Error::debug)?;
    module.function_meta(from_bytes)?;
    module.function_meta(from_string)?;
    module.function_meta(to_string)?;
    module.function_meta(to_bytes)?;
    Ok(module)
}

#[derive(Any)]
#[rune(item = ::json)]
/// Error type raised during JSON serialization.
struct Error {
    error: serde_json::Error,
}

impl Error {
    #[rune::function(vm_result, protocol = STRING_DISPLAY)]
    pub(crate) fn display(&self, f: &mut Formatter) {
        vm_write!(f, "{}", self.error);
    }

    #[rune::function(vm_result, protocol = STRING_DEBUG)]
    pub(crate) fn debug(&self, f: &mut Formatter) {
        vm_write!(f, "{:?}", self.error);
    }
}

impl From<serde_json::Error> for Error {
    fn from(error: serde_json::Error) -> Self {
        Self { error }
    }
}

/// Convert JSON bytes into a rune value.
/// 
/// # Examples
/// 
/// ```rune
/// let object = json::from_bytes(b"{\"number\": 42, \"string\": \"Hello World\"}")?;
/// assert_eq!(object, #{"number": 42, "string": "Hello World"});
/// ```
#[rune::function]
fn from_bytes(bytes: &[u8]) -> Result<Value, Error> {
    Ok(serde_json::from_slice(bytes)?)
}

/// Convert a JSON string into a rune value.
/// 
/// # Examples
/// 
/// ```rune
/// let object = json::from_string("{\"number\": 42, \"string\": \"Hello World\"}")?;
/// assert_eq!(object, #{"number": 42, "string": "Hello World"});
/// ```
#[rune::function]
fn from_string(string: &str) -> Result<Value, Error> {
    Ok(serde_json::from_str(string)?)
}

/// Convert any value to a json string.
/// 
/// # Examples
/// 
/// ```rune
/// let object = #{"number": 42, "string": "Hello World"};
/// let object = json::from_string(json::to_string(object)?)?;
/// assert_eq!(object, #{"number": 42, "string": "Hello World"});
/// ```
#[rune::function(vm_result)]
fn to_string(value: Value) -> Result<String, Error> {
    Ok(String::try_from(serde_json::to_string(&value)?).vm?)
}

/// Convert any value to json bytes.
/// 
/// # Examples
/// 
/// ```rune
/// let object = #{"number": 42, "string": "Hello World"};
/// let object = json::from_bytes(json::to_bytes(object)?)?;
/// assert_eq!(object, #{"number": 42, "string": "Hello World"});
/// ```
#[rune::function(vm_result)]
fn to_bytes(value: Value) -> Result<Bytes, Error> {
    Ok(Bytes::from_vec(Vec::try_from(serde_json::to_vec(&value)?).vm?))
}